Fig. 2: Band fillings of doubly aligned h-BN/graphene/h-BN superlattice.
From: Correlated states in doubly-aligned hBN/graphene/hBN heterostructures
a Schematics of h-BN/graphene/h-BN heterostructure with top and bottom h-BN (blue layer) perfectly aligned and the graphene (grey layer) slightly rotated at θG, with its band structure calculated in (b). c Illustration of bandwidth of the corresponding gaps in (b) as a function of θG. d Landau fan of sample S7 plotted in the space of ϕ/ϕ0 versus n/n0. ϕ/ϕ0 and n/n0 are the normalized magnetic flux and carrier density (see Eq. (1)), respectively. e Landau fan renormalised into a diagram defined by the Diophantine equation. Solid black lines are selected major Landau levels in (d). f Density of states (DOS) calculated from band structure in (b). g Field effect curves measured from different samples at B = 0 and T = 45 mK, with their twist angles obtained using Eq. (2). Solid black arrows in (g) indicate the correlated insulating states at integer fillings of −5, −6 and −7 n0. Vertical dashed lines in (f) and (g) correspond to band fillings.
